Sizing compositions and fibrous articles sized therewith



United States Patent l US. Cl. 117138.8 21 Claims ABSTRACT OF THEDISCLOSURE Fibrous articles (such as textile yarn, hemp rope, and tirecord) are sized with sizing compositions comprising linear,water-dissipatable polyesters derived from at least one dicarboxylicacid component, at least one diol component, at least mole percent ofsaid diol component being a poly(ethylene glycol), and a difunctionalmonomer containing a --SO M group attached to an aromatic nucleus,wherein M is hydrogen or a metal ion.

This invention relates to sizing compositions and to fibrous articlessized therewith. In one of its more specific aspects, this inventionrelates to sizing compositions for textile yarns made from linearpolyesters.

When textile materials are to be used in the form of multifilament yarnsfor the fabrication of textile materials, it is desirable before theweaving process to treat the warp yarn with a sizing composition(sometimes referred to as an agent) which adheres to and binds theseveral filaments together. This treatment strengthens the severalfilaments and renders them more resistant to abrasion during thesubsequent weaving operations. It is especially important that thesizing composition impart abrasion resistance to the yarns duringweaving because abrasion tends to sever the yarn and to produce endbreaks which, of course, lower the quality of the final woven product.It is also important that the sizing composition be one which can besubsequently removed from the yarns by scouring.

Various high molecular weight materials have been suggested as sizes foryarns. Among such materials are gelatin, sodium polyacrylate, polyvinylalcohol, and the sodium salt of a 50/50 maleic anhydride-styrenecopolymer. However, some of these materials are not readily compatiblewith or do not adhere well to textile yarns and thus do not form aprotective coating or film thereon. Other materials coat the yarn but donot impart more than a slight degree of abrasion resistance. Therefore,a I

need exists for sizing compositions which avoid the abovementioneddisadvantages.

It is an object of this invention to provide sizing compositions,fibrous articles sized therewith, and processes for sizing said fibrousarticles. Another object of this invention is to provide sizingcompositions for textile yarns, especially those yarns made from linearpolyesters. Still another object of this invention is to provide sizingcompositions which will adhere to and bind together the severalfilaments of textile yarns. Still another object of this invention istoprovide sizing compositions which will impart abrasion resistance totextile yarns during weaving. Yet another object of this invention is toprovide sizing compositions which can be removed from textile yarns byscouring. Other objects of this invention will appear herein.

These and other objects are attained through the practice of thisinvention, one embodiment of which comprises providing a fibrous articlesized with a sizing composition comprising a linear, water-dissipatablepolyester derived essentially from components (A) at least one di-3,546,008 Patented Dec. 8, 1970 carboxylic acid, (B) at least one diol,at least 20 mole percent of said diol component being a poly(ethyleneglycol) having the formula ntocn cn anon wherein n is an integer of fromtwo to about ten, and (C) a difunctional monomer containing a SO M groupattached to an aromatic nucleus, wherein M is hydrogen or a metal ion.

Another embodiment of this invention through which the above objects areattained comprises providing a process for sizing a fibrous article,wherein said process comprises applying to said fibrous article a sizingcomposition as described above.

The term dissipatable will be understood to refer to the action of Wateror an aqueous solution (preferably at least 25 percent by weight ofwater) on the polyester sizing composition. This term is specificallyintended to cover those situations wherein the polyester sizingcomposition is dissolved or dispersed in water or an aqueous solution.

We have discovered that the above-described noncrystalline polyestersare effective, when dissipated in water or aqueous solutions, as sizesfor a variety of natural and synthetic textile yarns. Examples of suchyarns include those made from polyesters, such as poly(ethyleneterephthalate) and poly(l,4-cyclohexylenedimethylene terephthalate),cotton, rayon, cellulose acetate, nylon, and polypropylene. Therefore,although this invention will be illustrated by references to polyesters,our sizing composition may be used on these other types of textilematerials with good results obtained.

The sizing compositions of this invention are particularly useful forsizing polyester yarn, which is among the most difficult of all textileyarns to size. In fact, presently no really effective sizing compositionis known for continuous filament polyester fibers, and an expensivetwist must be imparted to protect them during weaving. The sizingcompositions of this invention make it possible to weave low or zerotwist polyester fibers with substantially no defects.

It is necessary for greater effectiveness that a textile size besubstantially scoured or removed from the woven fabric so that it willnot interfere with subsequent finishing and dyeing operations. Inpractical terms, this means that the sizing composition must bewater-dissipatable (that is, either water-soluble or water-dispersible).The non-crystalline polyesters that are effective as sizes in theprocess of this invention contain a hydrophobic moiety and a hydrophilicmoiety. For example, a preferred sizing composition is prepared fromisophthalic acid, the sodium salt of 5-sulfoisophthalic acid, anddiethylene glycol. In this composition, the isophthalic acid ishydrophobic, the sodium sulfoisophthalic acid is hydrophilic, and thediethylene glycol is hydrophilic. This particular composition, whenadded to water, forms a dispersion which exhibits a dispersion viscosityhigher than that of water but lower than that which might be expected ifthe polymer were completely dissolved. As the temperature is raised from25 C. to about -C., no appreciable increase in dispersion or solutionviscosity results. Thus, this particular composition acts as if it werepartially soluble in water and partially insoluble, a behavior which isconsistent with its hydrophobic-hydrophilic composition. In addition,the hydrophilic portion of the molecule can be increased and acompletely water-soluble composition obtained. Conversely, thehydrophobic moiety of the polyester molecule can be increased and acomposition which is water-dispersible but which imparts little or noadditional viscosity to water can be used. It is desirable that the sizecomposition, on evaporation of the water, (1)

adhere to the fiber being sized, (2) form a sufficiently protective filmso that the fiber is protected during weaving, and (3) be removable fromthe fiber under ordinary conditions of scouring.

The efficiency of a material as a size can be determined by measuringits Duplan abrasion resistancethe higher the Duplan value, the better itprotects the yarn. The Duplan Cohesion Tester is a machine designed totest the effectiveness of a size solution by testing the cohesion of thesized filament yarn before the warp reaches the loom. Samples of sizedyarn under a constant tension are abraded by friction plates moving backand forth on the yarn at a constant rate. The average number of strokesper strand required to separate the filaments in ten strands of yarn arereported as the Duplan value. Forty tests on each sample are consideredthe standard test. In examining the strands at intervals for openplaces, an air jet is blown along each strand to assist in detectingopenings.

The novel sizes of this invention may be used in the following manner:the size, in powder or pellet form, is added to water at any convenienttemperature between somewhat below room temperature to about 100 C. andis subjected to mild agitation. Depending upon the specific propertiesof the particular composition being used, a clear to cloudy, moderatelyviscous, stable dissipation of the size in water is obtained.

The yarns to be sized are the highly polymeric, fiberand film-forming,linear polyesters derived from at least one aliphatic, cycloaliphatic,or aromatic dicarboxylic acid and at least one aliphatic,cycloaliphatic, or aromatic diol. The preparation of these polyestersand the spinning of fibers therefrom are well-known procedures and neednot be detailed herein. The acids and diols described below for thesizing composition are examples of components from which thesepolyesters can be prepared.

The dicarboxylic acid component from which the linear,water-dissipatable polyester sizing composition is prepared can be anyaliphatic, cycloaliphatic, or aromatic acid. Examples of suchdicarboxylic acids include oxalic; malonic; dimethylmalonic; succinic;glutaric; adipic; trimethyladipic; pimelic; 2,2 -dimethylglutaric;azelaic; sebacic; fumaric; maleic; itaconic;1,3-cyclopentanedicarboxylic; 1,2-cyclohexanedicarboxylic;1,3-cyclohexanedicarboxylic; 1,4-cyclohexanedicarboxylic; phthalic;terephthalic; isophthalic; 2,5-norbornanedicarboxylic; 1,4-naphthalic;diphenic; 4,4-oxydibenzoic; diglycolic; thiodipropionic;4,4'-sulfonyldibenzoic; and 2,5-naphthalenedicarboxylic acids. Ifterephthalic acid is used as the dicarboxylic acid component of thepolyester, especially good results are achieved when at least five molepercent of one or the other acids listed above is used.

It should be understood that the use of the corresponding acidanhydrides, esters, and acid chlorides of these acids is included in theterm dicarboxylic acid. The esters are preferred, examples of whichinclude dimethyl 1,4-cyclohexanedicarboxylate; dimethyl2,6-naphthalenedicarboxylate; dibutyl 4,4-sulfonyldibenzoate; dimethylisophthalate; dimethyl terephthalate; and diphenyl terephthalate.Copolyesters may be prepared from two or more of the above dicarboxylicacids or derivatives thereof.

At least about 20 mole percent of the diol component used in preparingthe polyester sizing composition is a poly(ethylene glycol) having theformula wherein n is an integer of from two to about ten. Examples ofsuitable poly (ethylene glycols) include diethylene, triethylene,tetraethylene, pentaethylene, hexaethylene, heptaethylene, octaethylene,nonaethylene, and decaethylene glycols, and mixtures thereof. Preferablythe poly- (ethylene glycol) employed in the polyester of the presentinvention is diethylene glycol, triethylene glycol, or mixtures thereof.The remaining portion of the diol component is at least one aliphatic,cycloaliphatic, r aromatic diol. Examples of these diols includeethylene glycol; propylene glycol; 1,3-propanediol;2,4-dimethyI-2-ethylhexane-1,3-diol; 2,2-dimethyl-1,3-propanediol;2-ethyl-2- butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-propanediol;1,3-butanediol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol;2,2,4-trimethyl-1,6-hexanediol; 1,2-cyc1ohexanedimethanol;1,3-cyclohexanedimethanol; 1,4-cyclohexanedimethanol;2,2,4,4-tetramethyl-1,3-cyclobutanedio1; and p-xylylenediol. Copolymersmay be prepared from two or more of the above diols.

A third component used to prepare the polyester sizing composition is adifunctional monomer containing a SO M group attached to an aromaticnucleus, wherein M is hydrogen or a metal ion. This difunctional monomercomponent .may be either a dicarboxylic acid (or derivative thereof)containing a SO M group or a diol containing a SO M group. The metal ionof the sulfonate salt group may be Na+, Li K+, Mg++, Ca++, Cu++, Fe, orFe+++. It is possible to prepare the polyester using, for example, asodium sulfonate salt and later by ion-exchange replace this ion with adifferent ion (for example, calcium) and thus alter the characteristicsof the polyester.

The SO M group is attached to an aromatic nucleus, examples of whichinclude benzene, naphthalene, anthracene, diphenyl, oxydiphenyl,sulfonyldiphenyl, and methylenediphenyl.

Especially good results are obtained when the difunctional monomer isthe sodium salt of a sulfoisophthalic, sulfoterephthalic, sulfophthalic,or 4-sulfonaphthalene-2,7- dicarboxylic acid (or derivatives of suchacids). A highly preferred such monomer is S-sodiosulfoisophthalic acidor a derivative thereof such as S-sodiosulfodimethyl isophthalate.Another preferred difunctional monomer is 5- sulfoisophthalic acid.Monomers containing a SO M group are described in Kibler et al. US. Ser.No. 695,- 339, filed Jan. 3, 1968 now abandoned in favor of acontinuation-in-part.

Other effective difunctional monomers containing a SO M group attachedto an aromatic nucleus include metal salts of aromatic sulfonic acids(or esters thereof). These monomers have the general formula wherein Xis a trivalent aromatic hydrocarbon radical, Y is a divalent aromatichydrocarbon radical, R is hydrogen or an alkyl group of one to fourcarbon atoms, M is hydrogen, Na+, Li+, K+, Mg++, Ca++, Cu, Fe, or Fe+++,and a is 1, 2, or 3. These monomers are described, including methods fortheir preparation, in Lappin et a1. U.S. Ser. No. 695,349, filed Jan. 3,1968 now US. Pat. No. 3,528,947, patented on Sept. 15, 1970. Examples ofpreferred monomers here are4-sodiosulfophenyl-3,S-dicarbomethoxybenzenesulfonate,4-lithiosulfophenyl-3,5-dicarbomethoxybenzenesulfonate; and6-sodiosulfo-2-naphthyl-3,5-dicarbomethoxybenzenesulfonate.

Other effective difunctional monomers containing a SO M group attachedto an aromatic nucleus include metal salts of sulfodiphenyl etherdicarboxylic acids (or esters thereof). These monomers have the generalformula ROOC s03- wherein R is hydrogen, an alkyl group of one to eightcarbon atoms, or phenyl, and M is hydrogen, Na Li+, Mg++, Ca++, Cu++,Fe++, or Fe+++ and a is 1, 2, or 3. These monomers are described,including methods for their preparation, in Lappin et al. US. Ser. No.671,565, filed Sept. 29, 1967 now abandoned and substituted bystreamlined continuation Ser. No. 835,295 which was published Nov. 18,1969 as a Defensive Publication, 868, 0.6. 730. Examples of preferredmonomers here are dimethyl 5- [4-(sodiosulfo)phenoxy] isophthalate,dimethyl 5- [4- (sdiosulfo)phenoxy] terephthalate, and -[4- (sodiosulfo)phenoxy1isophthalic acid.

The above-identified applications (U.S. Ser. Nos. 695,- 339; 695,349;and 671,565) are hereby incorporated by 6 0.25 gram of polymer per 100ml. of a solvent composed of 60 percent phenol and 40 percenttetrachloroethane.

Various additives may be incorporated into the sizing compositions toachieve specific results. Examples of such additives include talc -(toprevent the powder or pellets reference as a part of the presentspecification. 5 from adhering together), titanium dioxide, dyes, otherpig- When the difunctional monomer containing the --SO M ments, andstabilizers. groups is an acid or derivative thereof (such as itsester), The following examples are included for a better underthepolyester should contain at least about eight mole standing of thisinvention. percent of the monomer based o n total ac d content, withEXAMPLE 1 more than ten mole percent giving partlcularly advantageousresults. When the difunctional monomer is a diol, A InlXtuTe 0f gramsmolfi) Q dlmethyl the polyester should also contain at least about eightmole Phthalate, grams ((1125 mole) of by p percent of the monomer basedon total diol content, with e grams mole) Q heXahYdf010Phth111 more thanten mole percent giving particularly advanta- 15 mild, grams mole) ofdlmethyl5'sodlosulfolso geous results. Greater dissipatability isachieved when the Phthalate, grams mole) 0f q y q y difunctional monomerconstitutes from about 12 mole perf l a Percent catalyst SOhltlQIl 0ftltal'llllm cent to about 45 mole percent of the total content of acidISOPTOPOXIde 1S Stlfred a d heated at 200= and a or diol components ofthe polyester. vacuum of 0.3 mm. is applied. Heating and stirring iscon- To obtain the polyester sizing compositions of this intinued forone hour under these conditions. After cooling vention, the difunctionalmonomer containing the $O M the Polymer f llas of 053 and 1S tough groupmay be added directly to the esterification reaction and y- 1Sdlsslpated hot Water f The fiXteIlt mixture from which the polyesterwill be made. Thus, these 0f abpllt 20 Weight percent to glve p sllg y SHS ono can b d as a wmponent i th original solutlon. After storage ofthe solutlon for three months polyester reaction mixture. Other variousprocesses which r00m t pe atu e, the Water is evaporated from a pormaybe employed in preparing these sizing compositions The resldual} P y hasan -V- Of 15 N0 are well known in the art and are illustrated in suchpatmeasurable hydrolysls has Occurredents as US. 2,465,319; 3,018,272;2,901,466; and 3,075, EXAMPLE 2 952. These patents illustrate esterinterchange and p0- lyrnerization processes. The following table showsthe properties of a number Both the fiber-forming polyesters to be sizedand the of polyester sizing compositions made from difunctionalpolyester sizing compositions will have an inherent vismonomerscontaining SO M groups. All are made by cositv (I.V.) of at least 0.3,as measured at 25 C. using the general procedure of Example 1.

TABLE Mole Mole Mole Polymer Dicarboxylic acid Percent Sulfonate PercentDiol Percent I.V. {Isophthalic 52.5 7.5 DEG 3 100 4 A Terephthalic 25SIP 1 Hexahydroisophthalie 15 B Isophfhalit' 90 SIP 10 DEG 100 0.53 CHexahydroterephthahcn. 90 SI]? 10 DEG 100 0. 73

Isopht ic DEG D Tmrpphfhalic 25 SIP 10 EG 0.60

Hezahydroisophthalic 15 20 Isophthalic 50 E --{Terephthalic 25 10 DEG100 0.

Hexahydmisophthalic" 15 sopllillgh 1:0 10 DEG 100 0.48 G --{ri:3ah3tg;@g,rtsnm 30 i DEG 100 H Isophthalic 10 DEG 0. 42 I Terephthalie 92SIP 8 TEG 7 100 0.33 J Isophthalic 92 SIP 8 TEG 100 0. 59 K -410 90 SIP10 {g E g B 0. 45 L Adipic 90 SIP 10 100 0.69

- 50 M lsophthahc 90 SIP 10 5O 0. 48 N do 90 SIP 10 {ggg 0. 51 0 do s0SIP 20 {g gg 0.32 P- dn s0 SIP 20 {g gg 0.38

1 SIP-5-sodiosulfoisophthalic acid. 2 DEG-diethylene glycol. 3 EG-ethylene glycol.

4-sodiosulfophenyl-3,S-dicarboxybenzene sulionate,

HO O O HOOC/ 5 5-[4-(sodiosulfo)phenoxy1isophtha1lc acid, 0 O 0 H 52(2-sodiosu1iophenyl)Q-ethylmalonic acid, (I) O O H COOH S OaNB 7TEGtriethy1ene glycol.

B OHDM-1,4-cyclohexanedimethanol.

7 EXAMPLE 3 A mixture of 15 parts of the polyester sizing composition(I.V. of 0.5) derived from 90 mole percent isophthalic acid, 10 molepercent S-sodiosulfoisophthalic acid, and diethylene glycol and 85 partsof water gives a dispersion that is slightly hazy in appearance and thathas a Brookfield viscosity of 15. A poly(ethylene terephthalate) yarncontaining 40 filaments is passed through the aqueous dispersion of thesizing composition and dried. A 4.5 percent pickup of the size results.Pickup is a measurement of the weight percent of the size relative tothe weight of the sized yarn. The Duplan abrasion resistance of thesized yarn is 275, showing that this polyester is an excellent size forpolyester yarn.

EXAMPLE 4 The conditions of Example 1 are repeated except that 7.5 partsof the polyester sizing composition are suspended in 92.5 parts ofwater. A 2.7 percent pickup of size results. The Duplan abrasionresistance of this sized yarn is 244, indicating that this polyester isan excellent size for polyester yarns even at low pickup.

EXAMPLE 5 The conditions of Example 1 are repeated except that 12.5parts of gelatin are dissolved in 87.5 parts of water. The size pickupis not determined, but the supposedly sized polyester yarn has a Duplanabrasion resistance of only 13. This shows that gelatin is not asatisfactory size for polyester fibers.

EXAMPLE 6 The conditions of Example 1 are repeated except that 7.5 partsof the sodium salt of a 50/50 maleic anhydridestyrene copolymer aredissolved in 92.5 parts of water. Size pickup is not determined. Thesupposedly sized polyester yarn has a Duplan abrasion resistance of only8. This shows that this copolymer is not a satisfactory size forpolyester fibers.

It will be noted that in the preceding examples, size/ water ratios(weight/weight) of 15/85 and of 7.5/92.5 are used. However, thesize/water ratio may vary from 1/99 to 50/50.

When the size is a relatively hydrophobic, it does not impart muchviscosity to the aqueous size composition, and very high solids sizecompositions can be prepared. In addition, in the case of relativelyhydrophobic polyester sizes, very high molecular weight products-can beused without the formation of a size composition that is too viscous touse. This can be a real advantage when it is desirable to use, forexample, a high I.V. size material for high toughness. The extent towhich the yarn being sized pick up size will be affected by the solutionor suspension viscosity of the size composition, with more viscouscompositions in general leading to higher pickups." It is within thescope of this invention to add various thickening agents and the like tothe size composition to increase its viscosity.

Other polyester yarns and other polyester sizing compositions (such asthose from the table) can be substituted in the procedure of Example 1and good results obtained.

Although described above with particular reference to textile yarns,this invention encompasses fibrous articles in general, other examplesof which are tire cord (such as rayon, nylon, or polyester tire cord)and hemp rope. In sizing these other fibrous articles, this inventiondoes not necessarily require the removal of the sizing composition.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention as described hereinabove and as defined in the appendedclaims.

We claim:

1. A fibrous article sized with a sizing composition comprising alinear, water-dissipatable polyester derived essentially from components(A) at least one dicar-boxylic acid,

(B) at least one diol, at least 20 mole percent of said diol componentbeing a poly(ethylene glycol) having the formula HtOCH CH -hDH wherein nis an integer of from two to about ten, and

(C) at least one difunctional dicarboxylic acid sulfomonomer containinga SO M group attached to an aromatic nucleus, wherein M is hydrogen orNa+, Li+, K Mg++, Ca++, Cu++, Fe++, Fe+++, or a combination thereof,said sulfo-monomer component constituting at least about 8 mole percentto about 45 mole percent of the sum of the moles of said components (A)and (C).

2. A fibrous article as defined by claim 1 wherein said component (A) isisophthalic acid.

3. A fibrous article as defined by claim 1 wherein said component (A) isterephthalic acid.

4. A fibrous article as defined by claim 1 wherein said component (A) isadipic acid.

5. A fibrous article as defined by claim 1 wherein said component (A) ishexahydroterephthalic acid.

6. A fibrous article as defined by claim 1 wherein said component (A) isa mixture of isophthalic, terephthalic, and hexahydroisophthalic acids.

7. A fibrous article as defined by claim 1 wherein said component (B) isdiethylene glycol.

8. A fibrous article as defined by claim 1 wherein said component (B) istriethylene glycol.

9. A fibrous article as defined by claim 1 wherein said component (B) isa mixture of mole percent diethylene glycol and 20 mole percent ethyleneglycol.

10. A fibrous article as defined by claim 1 wherein said component (B)is a mixture of 70 mole percent diethylene glycol and 30 mole percent1,4-cyclohexanedimethanol.

11. A fibrous article as defined by claim 1 wherein said component (C)is 5-sodiosulfoisophthalic acid.

12. A fibrous article as defined by claim 1 wherein said component (C)is 4-sodiosulfophenyl-3,S-dicarboxybenzene sulfonate.

13. A fibrous article as defined by claim 1 wherein said component (C)is 5-[4-(sodiosulfo)phenoxy]isophthalic acid.

14. A fibrous article as defined by claim 1 wherein said component (C)is 2(2'-sodiosulfophenyl)-2-ethylmalonic acid.

15. A fibrous article as defined by claim 1 wherein said fibrous articleis a textile yarn.

16. A fibrous article as defined by claim 15 wherein said textile yarnis made from a polyester.

17. A textile yarn as defined by claim 16 wherein said polyester ispoly(ethylene terephthalate).

18. A textile yarn as defined by claim 16 wherein said polyester ispoly(l,4-cyclohexylenedimethylene terephthalate).

19. A fibrous article as defined by claim 1 wherein saidwater-dissipatable polyester has an inherent viscosity of at least about0.3, as measured at 25 C. at a concentration of about 0.25 gram of saidpolyester per ml. of a solvent composed of 60 percent phenol and 40percent tetrachloroethane.

20. A fibrous article as defined by claim 19 wherein said sulfo-monomercomponent constitutes at least about 12 mole percent of the sum of themoles of said component and 21. A fibrous article sized with a sizingcomposition comprising a linear, water-dissipatable polyester orpolyesteramide derived from at least two difunctional monomer componentswhich are dicarboxylic acid, hy-

droxycarboxylic acid having one aliphatic hydroxy group, aminocarboxylicacid, amino-alcohol having one aliphatic hydroxy group, a glycol havingtwo aliphatic hydroxy groups, and an organic diarnine includingcombinations thereof wherein the overall total moles of said monomercomponents comprises at least 10 mole percent of at least one or amixture of poly(ethylene glycols) containing from 2 to 10 ethyleneoxygroups and at least 4 mole percent of at least one or a mixture ofdifunctional sulfomonomer components containing at least one SO M groupattached to an aromatic nucleus, said nucleus being present in at leastone of the aforesaid monomer components wherein M is hydrogen or Na+,Li+, K+, Mg++, Ca++, Cu++, Fe++, Fe+++, or a combination thereof, saidpolyester or polyesterarnide having an inherent vis- 10 cosity of atleast about 0.1 measured as defined in this specification.

References Cited ALLAN LIEBERMAN, Primary Examiner L. T. JACOBS,Assistant Examiner US. Cl. X.R.

